Circuit interrupter



Jan. 17, 1950 B. P. BAKER 2,495,156

CIRCUIT INTERRUPTER Filed Dec. 15, 1945 s sh ts-sheet 1 .slls orWITNESSES: INVENTOR Jan. 17, 1950 B. P. BAKER 2,495,156

CIRCUIT INTERRUPTER Filed Dec. 15, 1945 a SheetsSheet 2 INVENTORBenjamin Pfia ker. @4 4 21/ ATTORN WITNESSES:

Jan. 17, 1950 B. P. BAKER 2,495,156

CIRCUIT INTERRUPTER Filed Dec. 15, 1945 3 Sheets-Sheet 3 WITNESSES:INVENTOR f%4 .Ben/am/h Ego/(er. Z. q 7 W Patented Jan. 17, 1950 CIRCUITINTERRUPTER.

Benjamin P. Baker, Turtle Creek, Pa., assignor to Westinghouse ElectricCorporation, East Pittsburgh, Pa., a corporation of PennsylvaniaApplication December 15, 1945, Serial No. 635,353

13 Claims.

This invention relates to circuit interrupters in general and, moreparticularly, to arc-extinguishing structures and contact arrangementstherefor.

A general object of my invention is to provide an improved circuitinterrupter which will not have its opening operation impeded by ice orsnow incrustation at the contact structure.

A more specific object of my invention is to provide an improved circuitinterrupter of the gas-blast type in which a portion of the opening gasor air is utilized to effect separating motion of a pair of contacts.

Another object is to provide an improved circuit interrupter of thegas-blast type incorporating a pair of arcing contacts and a pair ofserially related disconnect contacts in which opening air is employednot only to assist in separating motion of the disconnect contacts butalso is utilized to assist in extinguishing the residual current aredrawn at the disconnect contacts.

Further objects and advantages will readily become apparent upon areading of the following specification taken in conjunction with thedrawings, in which:

Figure 1 is a side elevational view of a gas-blast type of circuitinterrupter embodying my invention and shown in the closed circuitposition;

Fig. 2 is an enlarged substantially vertical sectional view taken alongthe line IIII of Fig. 1;

Fig. 3 shows a modified type of contact structure incorporating myinvention;

Fig. 4 shows still another modified type of contact structureincorporating my invention.

Fig. 5 is a vertical sectional view partially in elevation taken alongthe line V-V of Fig. 4;

Fig. 6 is a plan view of a modified type of disconnect contactstructure; and

Fig. 'I is a sectional view taken along the line VII-VII of Fi 6.

Referring to the drawings and more particularly to Fig. 1 thereof, thereference numeral l designates a base formed of structural steel whichsupports in place a tank 2 of compressed gas, in this instance air.Supported on top of the base I are three insulator columns, only two ofwhich appear in Fig. 1, and are respectively designated by the referencenumerals 3, 4. The three insulator columns support a mechanism housing5, which encloses a suitable pneumatic mechanism, not shown, for causingseparating upward pivotal movement of a blade-shaped movable disconnect2 structure generally designated by the reference numeral 1, and shownmore clearly in Fig. 2.

The mechanism housing 5 supports an insulator column 8 at the upper endof which is supported an arc-extinguishing structure, generallydesignated by the reference numeral 9. Disposed within thearc-extinguishing structure 9 are two serially related movable arcingcontacts l0, II which are simultaneously separable from a conductingplate l2.' Two insulating plates l3, H are spaced by tubular spacers l5which extend through the insulating plates l3, It, as well as throughthe conducting plate 12. Thus, it is possible for arc-extinguishing gasin the region It to pass upwardly through the tubular spacers l5 intothe region H.

The movable arcing contacts II), II are respectively secured to pistonmembers l8, is which are.

movable in piston chambers 20, 2|. The pistons I8, is are respectivelybiased by compression springs Ha, Ha to the closed position shown inFig. 1. The piston chamber 20 comprises a conducting tube having anannular gas conducting space between it and the inner wall of the insu-Y lator column 8. The opposed inner ends of the piston chambers 20, 2|serve to direct compressed gas through orifices 22, 23, provided in theinsulating plates l3, H. The compressed gas after passing through theorifices 22, 23 vents radially outwardly between the insulating platesI3, I and the conducting plat [2. Suitable cooling means, not shown, maybe provided to cool the ionized arc gases before they leave thearcextinguishing structure 9 through the louvers 24.

The sequencing within the mechanism housing 5 is such that the movabledisconnect contact 8 does not pivotally move upwardly until the arcsdrawn within the arc-extinguishing structure 9 are fully extinguished.

Extending upwardly from the arc extinguisher 9 is an insulator column 25which supports the line terminal 26 of the interrupter. The'stationarydisconnect contact structure I is supported at the upper end of aninsulator column 21, in the interior of which is disposed suitablemetering equipment. At the top of the insulator column 21 is secured theright-hand line terminal 28 of the interrupter.

From the foregoing description, it will be apparent that in the closedcircuit position of the inter rupter, as shown in Fig. 1, the electricalcircuit therethrough includes the line terminal 25, conducting pistonchamber 2l, movabl arcing contact ll, conducting plate l2, movablearcing concontaot 6 from a stationary disconnect contact mm; lo, nd tinl t chamber 39, by suitable housing 5.

. drawn within 3 connector means, not shown, to the movable disconnectcontact 6. The circuit then extends through the stationary disconnectcontact structure l and through metering equipment disposed within theinsulator column 21 to the right-hand line terminal 28 of theinterrupter.

To eflect the opening operation of the interrupter, valve structure 29is actuated to permit an opening blast of gas to pass from the manifold3|) upwardly through the valve housing 3| and upwardly through theinsulator column 3 to the pneumatic mechanism disposed within the Theblast of gas passes through suitable conduit means provided within theinterior of the housing 5 and upwardly around the piston chamber 20. Theopening blast of gas then passes into the region l6 and upwardly throughthe tubular spacers It to the region II. The compressed gas within theregions l6, l1 acts upon the piston members l3, is to force them andconsequently the movable arcing contacts I, II apart to draw twoserially related arcs extending between the tips of the arcing contactsand the conducting plate l2.

The compressed gas within the regions l6, l1 passes through the orifices22, 23 eilfecting extinction of the two serially related arcs therein tovent radially outwardly out of the arc-extinguishing structure 9 betweenthe insulating plates |3. l4 and the conducting plate l2.

Following interruption of the two serially related arcs the pneumaticmechanism disposed within the housing 6 is actuated to cause pivotalcounterclockwise rotation of the movable disconnect contact 6 upwardlyaway from the stationary disconnect contact structure 1. Followingseparation of the disconnect contacts 6, 1, suitable means, not shown,may be provided to close the valve structure 29 to cease the upwardpassage of gas from the manifold 30. At this time the springs Ila, Isawill close the arcing contacts III, II.

Impedance means in two resistors this instance including 32, 33 shuntthe are which are the arc extinguisher 9. More specifically, theresistors or impedance means 32, 33 have a tap connection 34 leading tothe conducting plate l2. The resistor 32 has a lead 35 connected to theline terminal 26. The resistor 33 has a connector 36 terminating at themetallic housing 5. Consequently, the impedance means which 1 provide toshunt the arcing contacts IO, N permits a residual current to passtherethrough following are interruption, which residual'current must beinterrupted at the disconnect contacts 6, I. If the impedance means 32,33 is not employed, the disconnect contact structure need not open anycurrent whatsoever,

the circuit being entirely broken at the arcing contacts III, II withinthe arc extinguisher 6. A conduit 31 connects with the blast tube 38 andis coupled by a coupling 39 to a ceramic tube 40 which extends upwardlythrough the interior of the insulator column 21 to the stationarydisconnect contact structure 1.

Referring to Fig. 2, which shows more clearly than Fig. 1, theconstruction of the stationary disconnect contact structure I, it willbe observed that the stationary disconnect contact structure I is of thejaw type including two opposed finger contacts 4|, 42 of right-angleconstruction, which are bolted at their ends by bolts 43 to adish-shaped metallic member 44 which also supports a metallic diaphragm45, a gasket 46' being employed to prevent gas leakage. It will beobwill be observed that iii) served from the foregoing description thatshould the contact structure 6, 1 be incrusted with ice formation, thepassage of gas upwardly through the conduit 4|) during the openingoperation will cause upward flexing of the diaphragm to cause a slightseparating pivotal movement of the stationary disconnect fingers 4|, 42to eilect release of the movable blade-shaped disconnect contact 6.

It will be observed that with the construction shown, the operation ofthe diaphragm 45 is not impeded by any ice formation at the contactstructure. It will also be observed that considerable torque actiontakes place to thereby bring into play large forces in causingseparation of the disconnect contacts.

In the modified type of stationary disconnect contact structure 41 shownin Fig. 3, it will be observed that a block 48 is secured as by weldingto the center of the diaphragm 46. The stationary disconnect fingercontacts 4|, 4Lare pivotally mounted at 49, 66 to the block 48. Thelower ends of the stationary disconnect fingers 4|, 42 have offstandinglug portions ii to which are riveted flexible straps 62 carrying thecurrent by means of the bolts 43 to the dish-shaped metallic member 44.

From the aforesaid construction it will be apparent that the passage ofopening gas through the conduit 40 will cause upward flexing motion ofthe diaphragm 45 to take place, which will cause outward separatingmotion of the disconnect fingers 4|, 42. The upper ends of thedisconnect flngers 4|, 42 are pivotally connected at 53, 64 to springguide rods 66, 68, the lower ends of which pass through apertures 51provided in lug portions 58 or the member 44. A compression spring 59encircles each spring guide rod 85, 56 and serves to supply contactpressure in the closed position, as shown in Fig. 3. During the openingoperation, the rods 55. 66 cooperate with nuts 60, secured to the lowerends thereof, to limit the inward motion of the stationary disconnectfingers 4|, 42.

In the construction shown in Figs. 4 and 5, it

I have not only used a portion of the opening gas to efiect release ofthe disconnect contact structure, but have also utilized a portion ofsaid gas to assist in extinguishing the residual current arc drawn atthe disconnect contact structure should impedance means 32, 33 beemployed shunting the main arcing contacts III, II. Thus, the conduit 40has connected thereto a conduit 6| which has its end 62 so directed asto direct opening as or air adjacent the separating disconnect contactsto assist in extinguishing the residual current are drawn between themovable disconnect contact 6 and the stationary disconnect contactfingers 4|, 42. Preferably, a flap valve 62a is biased by a leaf spring62b against a ing portion 620 of the grind-nit 6| to prevent rainentering the conduit Bracket means 63, in this instance consistingrelate flexing motion of the diaphragm 45 with separating motion of thestationary disconnect contact fingers 4|, 42. The right-angle brackets64 are secured by bolts 65 to the supporting structure 66 and have sideportions 61 resting against the face of the diaphragm 45. The other side68 of the right-angle bracket 64 has an aperture 68 providedtherethrough through which extends a rivet 10 having a head 1|. Therivet I0 is secured to the disconnect fingers 4|, 42 and serves to causethe disconnect fingers 4|, 42 to be moved apart upon flexing of theright-angle bracket 54 in response-to flexing of the diaphragm 45. Inthis construction, it will be noted that the contact fingers 4 I, 42stand out and are well drained. It will also be noted that the flexingof the diaphragm 45 causes separating motion of the stationarydisconnect fingers 4|, 42 to effect releasement between the movable anddisconnect contacts even though ice may be incrusted thereat.

In the modified type of stationary disconnect contact structure 12 shownin Figs. 6 and 7 it will be observed that the conduit 40 leads into acup-shaped member I3 having an annular deflector 14 secured, as bywelding, to the upper end thereof. The metallic diaphragm 45 has a rod15 secured to the center portion thereof as by welding. To the lower endof the rod 15 is secured a spider 16 which serves as a lower seat for acompression spring 'll, the upper end of which seats against an inwardlyextending flange I8 secured as by welding to the interior face of thecup-shaped member 13.

Preferably, flexible shunts 19 are employed to electrically interconnectthe spider 16 with the flange 18 to carry the current of the disconnectcontacts. The blade-shaped movable disconnect contact 6 again slidesbetween the stationary disconnect finger contacts 4|, 42 which haveportions 80 seated nearer the center portion of the diaphragm 45. Thestationary disconnect finger contacts 4|, 42 have horizontal portions 81which are secured by screws 82 to a ring 83 which is secured to thediaphragm 45 by any suitable means, such as by brazing. It will be notedthat the metallic diaphragm 45 seats upon a gasket 84 disposed in anannular groove 85 provided at the upper end of the cup-shaped member 13.

The opening of the modified type of stationary disconnect contactstructure 12 will now be described. Following the "opening of the arcingcontacts II], I l to interrupt the main circuit passing through theinterrupter, there still remains a residual current which passes throughthe resistors 32, 33 and consequently through the movable and stationarydisconnect contact structure including the flexible conductors 19. Theupward passage of opening air through the conduit 40 strikes themetallic diaphragm 45 to cause a deflection of the same, thereby flexingthe stationary disconnect contact fingers 4|, 42 outwardly to break anyice formation incrusted' thereat. Following the deflection of themetallic diaphragm 45 to efiect opening of the disconnect contactstructure, the air pressure further acts over the entire surface of theldiaphragm 45 to bodily raise the same upwardly away from the gasket 84against the downward biasing action exerted by the compression spring11. After the diaphragm 45 together with the stationary disconnectcontact fingers 4|, 42 has raised, the air is then permitted to passaround the diaphragm 45 and to be deflected by the deflector 14 toextinguish any residual current are which is drawn between the movablebladeshaped disconnect contact and the stationary disconnect contactfingers 4|, 42. Thus, it will be observed that in this embodiment of myinvention the directing of the gas flow about the diaphragm 45 isreadily obtained to effect a rapid extinction of the residual currentare drawn at the disconnect contact structure.

From the foregoing description it will be apparent that I have providedan improved outdoor compressed gas circuit interrupter which preventsthe incrustation of ice at the disconnect contact structure frominterfering with the operation of the disconnect contacts. I haveaccomplished this by utilizing diaphragm means which is acted upon by aportion of the opening air fed from the blast tube 38. Also, I haveshown a means whereby not only is the opening air utilized to effectseparation of the disconnect contact structure, but it is also used tohelp extinguish the residual current are drawn at the disconnect contactstructure should impedance means 32, 33 be employed to shunt the mainarcing contacts Ill, II. The concept of utilizing opening air to effectextinction of the residual current are at the disconnect contactstructure is described and claimed in the United States patentapplication, Serial No. 624,284, filed October 24, 1945, by Benjamin P.Baker and Oswald von Mehren, and assigned to the assignee of the instantapplication.

It will also be noted that I have provided an improved contact structurewhich is applicable not only to circuit interrupters of the outdoorcompressed gas type, but is also applicable to any type of circuitinterrupter where because of weather conditions ice may be formed at thecontact structure. By an application of my invention to such a type ofcircuit interrupter, releasing of the contact structure against frictionand corrosion even though ice or snow may not be present is obtained tothereby bring about rapid contact separating motion.

Although I have shown and described specific structures, it is to beclearly understood that the same were merely for the purpose ofillustration and that changes and modifications may be readily madetherein by those skilled in the art without departing from the spiritand scope of the appended claims.

I claim as my invention:

1. In a circuit interrupter, a stationary jawshaped contact includingtwo opposed finger contacts, a movable contact cooperating with saidfinger contacts, a diaphragm, a block secured to the center of thediaphragm, the two finger contacts being pivotally mounted to the block,and means for applying gas pressure to one side of the diaphragm to flexsaid diaphragm to move said finger contacts away from said movablecontact.

2. In a circuit interrupter, a movable bladeshaped contact, a jaw-shapedcontact including two opposed finger contacts, a diaphragm, bracketmeans mounted against the diaphragm, means interconnecting the bracketmeans to the finger contacts, means applying gas pressure to one side ofthe diaphragm, and the flexing of the diaphragm causing through thebracket means separating motion of the finger contacts.

3. In a circuit interrupter of the gas-blast type, a pneumatic operatingmechanism, a pair of arcing contacts, serially related disconnectcontacts comprising a movable contact and opposed stationary contactsengaging said movable contact, impedance means shunting the arcingcontacts, means comprising a diaphragm flexed by opening gas anddisposed to efiect separating movement of said opposed contacts torelease said movable contact, and means employing opening gas to assistin interruption of the residual current are established at thedisconnect contacts.

4. In a circuit interrupter of the gas-blast type, a pneumatic operatingmechanism, a pair of arcing contacts, serially related disconnectcontacts comprising a pair of opposed stationary contacts and a movablecontact, a diaphragm operable to move said opposed stationary contactsaway from said movablecontact, means permitting opening gas to act onone side of the diaphragm to flex said diaphragm, and meansinterrelating flexing of the diaphragm with separating motion of thedisconnect contacts to eiIect movement of said opposed stationarycontacts away from said movable contact during the separating movementof said disconnect contacts.

5. In a circuit interrupter of the gas-blast type, a pneumatic operatingmechanism, a pair of arcing contacts, serially related disconnectcontacts comprising a movable contact and a pair of opposed stationarycontacts, a diaphragm flexible to move said opposed stationary contactsaway from said movable contact, means permitting opening gas to act onone side of the diaphragm to fiex said diaphragm, means interrelatingflexing oi the diaphragm with separating motion of the disconnectcontacts, impedance means-shunting the arcing contacts, and meansemploying opening gas to assist in interruption oi the residual currentare established at the disconnect contacts. V

6. In a circuit interrupter, a movable contact, opposed stationaryfinger contacts resiliently embracing said movable-contact in the closedcircuit position, and pneumatic means comprising a diaphragm operableduring the opening operation to cause outward separating motion of thestationary finger contacts away from said movable contact to efl'ectrelease of the movable contact.

7. In a circuit interrupter, a movable contact cooperable with astationary contact, a diaphragm, means permitting gas pressure to actupon one side of the diaphragm, means responsive to movement of thediaphragm to eifect releasing engagement between the stationary andmovable contacts, and means for permitting a portion of s the gas topass around the diaphragm to assist in eii'ecting the extinction of anyare drawn at the contacts.

8. In a circuit interrupter, a. movable disconnect contact a diaphragm,a pair of opposed finger contacts having portions thereof restingagainst the face of the diaphragm, said finger contacts having otherportions engaging said disconnect contact and means for applying gaspressure to the opposite face of the diaphragm during the openingoperation to cause flexing thereof thereby resulting in outwardseparating motion of the pair of finger contacts to release said movabledisconnect contact.

9. In a circuit interrupter, a cup-shaped member having a deflectorsecured to the upper end thereof, a diaphragm covering the upper end of8 the cup-shaped member, means biasing the diaphragm to the closedposition, a pair of finger contacts having portions thereof in abuttingengagement with the upper face of the diaphragm, and means for applyinggas, pressure to the diaphragm during the opening operation.

10. In a circuit interrupter, a movable contact stationary contact meanscomprising opposed contacts resiliently engaging opposite sides of saidmovable contact, diaphragm means in operative engagement with thestationary contacts, and means for applying gas pressure to thediaphragm means for flexing said diaphragm to eiiect releasing movementof said stationary contacts.

11. In a circuit interrupter, a movable contact cooperable with astationary contact, diaphragm means in operative engagement with thestationary contact, means for applying gas pressure to the diaphragmmeans to elect release of the movable and stationary contacts, and meansfor permitting a portion of the gas to by-pass the diaphragm means toassist in eii'ecting the extinction of any are drawn at the contacts.

12. A circuit interrupter including a pair of opposed stationarycontacts. a cooperating movable contact engageable between saidstationary contacts, a diaphragm cooperating with said stationarycontacts, and valve means for admitting fluid pressure to one side ofsaid diaphragm to effect movement of said stationary contacts away fromsaid movable contact to release said movable contact.

13. A circuit interrupter including stationary jaw-shaped contact means,a movable contact cooperating with said stationary contact means to openand close the circuit, fluid pressure operated means operable to movesaid stationary contact means away from said movable contact, fluidpresure operated means for moving said movable contact to open position,and a valve for admitting fluid pressure to both of said pressureoperated means.

BENJAMIN P. BAKER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,582,154 Zeiher, et al Apr. 27,1926 2,250,216 Biermanns July 22, 1941 2,306,186 Rankin Dec. 22, 19422,365,134 Amer, et a1. Dec. 12, 1944 2,379,761 Strang July 3, 1945

